"The Prime Minister has tonight passed on her condolences to President Hollande."

The incident comes days before the French election, which is to take place on Sunday.

President Francois Hollande called an emergency meeting on Thursday evening and said at a press conference that he was convinced the attack was a terrorist act.

US president Donald Trump, speaking at a press conference in Washington, said the incident "looks like another terrorist attack" and sent his condolences to France.

Steve White, chairman of the Police Federation of England and Wales, said: "Once again the police family is in mourning and it serves to underline how brave officers are putting their life on the line day in and day out to protect the public.

"As French colleagues felt the pain of our loss in Westminster last month, we feel theirs tonight."

Pictures of the scene in Paris showed people rushing to clear the area, and a heavy armed police presence.

Eyewitness Badi Ftaiti said: "They were running, running.

"Some were crying. There were tens, maybe even hundreds of them."

After the shooting, police swooped on an address in a Paris suburb.

A police document obtained by The Associated Press identifies the address searched in the town of Chelles as the family home of 39-year-old convicted criminal Karim Cheurfi.

Archive reports by French newspaper Le Parisien say he was convicted of attacking a police officer in 2001.